The inventive concept relates to non-volatile memory devices and more particularly to methods of reading data from non-volatile memory devices.
Semiconductor memory devices may be classified into volatile and non-volatile memory devices according to whether stored data is retained in the absence of applied power. Non-volatile memory devices such as flash memory devices perform write (program) and erase operations with respect to each block or sector composing the block. As the write and erase operations are repeatedly performed, the threshold voltage distribution of memory cells may broaden or shift. Therefore, read voltages used to read data from such non-volatile memory devices must be precisely controlled during a read operation. Unfortunately, precise control over the definition read voltages takes additional time, thereby undesirably extending the duration of read operations.